Just because you've grown into a responsible adult doesn't mean you can't occasionally enjoy the simple pleasure of building a pillow fort. But why stop at the crude one-person shacks you built as a kid? With this calculator, and plenty of disposable income, you can assemble a cushion command center on a much grander scale.

History tells us that the Alamo was an effective spot to fend off attackers, and with 3,807 cushions (costing just over $316,000) you can build your own to protect you from invading co-workers or siblings. If you've got an extra $120 million lying around you can even rebuild the Pentagon with over 1,440,000 cushions, but that seemingly doesn't include the cost of sheets needed to also put a massive roof over your head. [Movoto]